When a tire attached to an automobile has an elastic modulus, a dimension, or a shape which is not constant in the circumferential direction thereof, the tire generates a vibration in a high-speed rotation state and hence degrades a running performance. For this reason, an examination is performed by a tire testing machine so as to determine whether a vulcanized and patterned tire is uniform in the circumferential direction.
Hitherto, as such a tire testing machine, there is known a tire testing machine including a rim member into which a bead portion of an inner periphery of a tire is fitted, a rotatable spindle to which the rim member is attached, a member that applies a predetermined internal pressure to the tire, and a road surface substituting member such as a drum which is pressed against an outer periphery of the tire. In the tire testing machine, the tire fitted into the rim member is rotationally driven by the rotation of the spindle, and the rotating tire contacts the road surface substituting member, thereby measuring the uniformity of the tire in the circumferential direction. In general, lubricant is applied to the bead portion of the tire to be tested so as to smoothly fit the tire into the rim member.
As such a tire testing machine, there is known a tire testing machine further including a loading device which feeds a tire to be tested to a testing station conveyor with the spindle and the like. The loading device includes a conveyor which conveys the tire, and feeds the tire to a position where the center of the tire matches the spindle. Further, as the loading device, there is known a loading device which includes a lubricator for applying lubricant to a bead portion of the inner periphery of the tire conveyed on the conveyor.
For example, Patent Document 1 discloses a tire testing machine including a tire testing station which includes a spindle provided vertically, a centering station which is provided at a position separated from the spindle by a predetermined distance and centers the tire to be tested, and a loading device which feeds the tire in a laid state from the centering station to the tire testing station so as to attach the tire to the spindle in a laid state. Alternatively, there is also known a tire testing machine in which a spindle is provided sideways and a tire is attached to the spindle in an upright state. The centering station of the tire testing machine disclosed in Patent Document 1 includes a unit which rotates the centered tire and an applicator which applies lubricant to a bead portion of the inner periphery of the rotating tire. The conveyor of the tire testing machine may feed the centered tire from the centering station to the center position of the spindle of the tire testing station by normally conveying the tire by a predetermined distance.
In the above-described loading device for the tire testing machine, it is an important issue to shorten the feeding time necessary for feeding the next tire staying at the standby position such as the centering station to the spindle attachment position after the test of the tire attached to the spindle ends. The shortening of the feeding time leads to the shortening of the testing cycle time. However, it is not desirable to excessively increase the conveying speed for the purpose of shortening the feeding time from the viewpoint of the design and the safety of the device.